Stable dispersion concentrates

ABSTRACT

The invention provides stable dispersion concentrates comprising:  
     I) 5 to 80% by weight, preferably 10 to 80% by weight, particularly preferably 20 to 60% by weight, especially preferably 30 to 40% by weight, of a polymer which, in random distribution, consists of 90 to 99.99% by weight of monomers of the formula (1)  
     H 2 C=CHCONHC(CH 3 ) 2 CH 2 SO 3 X  ( 1 )  
      and 0.01 to 10% by weight of crosslinking structures originating from monomers with at least two olefinic double bonds, where X is a cation or a mixture of cations, and X must consist of not more than 10 mol % of protons,  
     II) 20 to 95% by weight of one or more emulsifiers and/or an oil phase, and  
     III) 0 to 30% by weight of water.

[0001] The present invention relates to dispersion concentratescomprising polymers based on acryloyldimethyltauric acid or saltsthereof (AMPS).

[0002] These polymers, described in EP 816 403, based onacryloyldimethyltauric acid and salts thereof, preferably prepared byprecipitation polymerization, confer broad performance properties andcan be used as thickener, bodying agent, emulsifier, dispersant,lubricant, conditioner and/or stabilizer in cosmetic, dermatological andpharmaceutical compositions.

[0003] The polymers based on AMPS, prepared preferably by precipitationpolymerization, in accordance with the prior art are pulverulentsubstances with performance disadvantages resulting therefrom. Inaddition to a risk of dust explosion, the dust can harbor dangers incases of inhalation, and also the storage stability of the powders isimpaired by hygroscopicity.

[0004] When processing or using the pulverulent products, thedissolution operation (the polymers are preferably incorporated intoaqueous media) is in most cases very time-consuming. The dissolutionoperation of the pulverulent products can, depending on the size of thebatch, take one hour and more. In addition, incompletedissolution/swelling of the pulverulent products is often observed,which leads to a reduction in the quality and stability of the endformulation (formation of lumps). In addition, the processing and/or useof the pulverulent products generally requires specific stirring anddispersion devices in order to dissolve, or suspend, the AMPS polymersin the compositions.

[0005] The object was to find liquid forms of the pulverulent polymers,described in the abovementioned applications, based onacryloyldimethyltauric acid or salts thereof, preferably prepared byprecipitation polymerization (AMPS). Preference is given here todispersions of the polymers in a liquid matrix comprising oil,emulsifier, dispersant and/or water. Preference is given here toliquid-disperse forms with the highest possible polymer proportion, lowviscosity coupled with high stability of the dispersion. The oil andemulsifier/dispersant proportions used are preferably cosmetically andpharmaceutically acceptable raw materials.

[0006] Surprisingly, it has been found that AMPS polymers are suitablein an excellent manner for the preparation of dispersion concentrates.

[0007] The invention provides stable dispersion concentrates comprising

[0008] I) 5 to 80% by weight, preferably 10 to 80% by weight,particularly preferably 20 to 60% by weight, especially preferably 30 to40% by weight, of a polymer which, in random distribution, consists of90 to 99.99% by weight of monomers of the formula (1)

H₂C=CHCONHC(CH₃)₂CH₂SO₃X  (1)

[0009]  and 0.01 to 10% by weight of crosslinking structures originatingfrom monomers with at least two olefinic double bonds, where X is acation or a mixture of cations, and X must consist of not more than 10mol % of protons,

[0010] II) 20 to 95% by weight, preferably 20 to 90% by weight,particularly preferably 40 to 80% by weight, especially preferably 60 to70% by weight, of one or more emulsifiers and/or an oil phase, and

[0011] III) 0 to 30% by weight, preferably 0 to 10% by weight,particularly preferably 0 to 5% by weight, of water.

[0012] Preferably, the dispersion concentrates according to theinvention comprise polymers containing 98 to 99.5% by weight of radicalsof the formula (1) and 0.5 to 2% by weight of crosslinking structuresoriginating from monomers with at least two olefinic double bonds.

[0013] The symbol X in the formula 1 is, in particular, a proton, acation of an alkali metal, an equivalent of a cation of an alkalineearth metal or an ammonium ion.

[0014] Particularly preferred polymers comprise 90 to 100 mol % of thecations X from ammonium ions and 0 to 10 mol % of protons.

[0015] Crosslinkable structures originating from monomers with at leasttwo olefinic double bonds are preferably derived from, for example,dipropylene glycol diallyl ether, polyglycol diallyl ether, triethyleneglycol divinyl ether, hydroquinone diallyl ether, tetraallyloxyethane orother allyl or vinyl ethers of multifunctional alcohols, tetraethyleneglycol diacrylate, triallylamine, trimethylolpropane diallyl ether,methylenebisacrylamide, divinylbenzene or trimethylolpropanetri(meth)acrylate.

[0016] The polymers used according to the invention in dispersionconcentrates can be prepared by free-radical polymerization of 90-99.99%by weight of the compound of the formula (1) and 0.01-10% by weight ofone or more crosslinkers which contain at least two olefinic doublebonds.

[0017] Preferably, these polymers are prepared

[0018] a) by dissolving or dispersing the compound of the formula (1) ina solvent or solvent mixture, where X can in this case also consist ofup to 100 mol % of protons;

[0019] b) optionally neutralizing the resulting solution or dispersionby means of one or more bases, so that at least 90 mol % of the sulfonicacid is converted into the salt form,

[0020] c) adding one or more crosslinkers with at least two olefinicdouble bonds to the solution or dispersion obtained as in a) and b) and

[0021] d) starting the polymerization in a manner known per se usingfree radical-forming compounds at a temperature of from 10 to 150° C.,where the solvent or solvent mixture mentioned in a) is chosen such thatthe resulting polymers are largely insoluble in the solvent or solventmixture.

[0022] Specifically, the described polymers can be prepared byprecipitation polymerization as follows. The reaction medium used ispreferably a water-soluble alcohol or a mixture of two or morewater-soluble alcohols with 1 to 4 carbon atoms, preferably intert-butanol, where the water content of the alcohol or alcohol mixturemust not exceed 10% by weight. The type and amount of solvent is chosenso that the amount used of 2-acrylamido-2-methylpropanesulfonic acidand/or the salt to be polymerized is largely soluble or dispersible.Largely soluble or dispersible is understood as meaning that, after thestirrer has been scraped off, no solid material settles out from thesolution or dispersion. The polymer which forms in the course of thereaction, by contrast, should, however, be largely insoluble in thechosen solvent (or solvent mixture). Largely insoluble or dispersible isunderstood as meaning that, also after switching off the stirrer, nosolid material settles out of the solution or dispersion. The polymerwhich forms in the course of the reaction, by contrast, should, however,be largely insoluble in the chosen solvent (or solvent mixture). Largelyinsoluble is understood here as meaning that, in the course of thepolymerization, a readily stirrable slurry-like polymer mass is producedin which no lumps or agglutinations may form. The filtrate obtainable byfiltering the paste with suction should have a solids content of at most5% by weight. If the polymers are soluble to a greater extent in thechosen solvent or solvent mixture, lumps may result as the polymer pasteis dried.

[0023] The polymerization reaction itself is triggered in a manner knownper se using free radical-forming compounds, such as azo initiators(e.g. azobisisobutyronitrile), peroxides (e,g, dilauryl peroxide) orpersulfates in a suitable temperature interval from 20 to 120° C.,preferably between 40 and 80° C., and continued over a period of from 30min to several hours.

[0024] As well as comprising the copolymer, the dispersion concentratesaccording to the invention also comprise one or more emulsifiers and/oran oil phase in the stated amount. If emulsifiers are used as the solecomponent II, the proportion of the oil phase is thus 0% and,accordingly, the proportion of the emulsifiers is 0%, if the componentII consists only of an oil phase. Preference is given to using a mixtureof emulsifier and oil phase as second component.

[0025] Suitable emulsifiers are addition products of from 0 to 30 mol ofalkylene oxide, in particular ethylene oxide, propylene oxide, butyleneoxide onto linear fatty alcohols having 8 to 22 carbon atoms, onto fattyacids having 12 to 22 carbon atoms, onto alkylphenols having 8 to 15carbon atoms in the alkyl group and onto sorbitan esters;(C₁₂-C₁₈)-fatty acid mono- and diesters of addition products of from 0to 30 mol of ethylene oxide onto glycerol; glycerol mono- and diestersand sorbitan mono- and diesters of saturated and unsaturated fatty acidshaving 6 to 22 carbon atoms and optionally their ethylene oxide additionproducts; addition products of from 15 to 60 mol of ethylene oxide ontocastor oil and/or hydrogenated castor oil; polyol and, in particular,polyglycerol esters, such as, for example, polyglycerol polyricinoleateand polyglycerol poly-12-hydroxystearate. Preference is given to liquidfatty acid esters which may either be ethoxylated (PEG-10 polyglyceryl-2laurate) or nonethoxylated (polyglyceryl-2 sesquiisostearate).

[0026] Further dispersion concentrates according to the inventionpreferably comprise sorbitol ester prepared by reacting sorbitol withfatty acid methyl esters or fatty acid triglycerides. The fatty acidradical in the fatty acid methyl esters and fatty acid triglyceridesgenerally comprises 8 to 22 carbon atoms and can be straight-chain orbranched, saturated or unsaturated. Examples thereof are palmitic acid,stearic acid, lauric acid, linoleic acid, linolenic acid, isostearicacid or oleic acid. Suitable fatty acid triglycerides are all naturalanimal or vegetable oils, fats and waxes, for example olive oil,rapeseed oil, palm kernel oil, sunflower oil, coconut oil, linseed oil,castor oil, soybean oil, optionally also in refined or hydrogenatedform. Since these natural fats, oils and waxes are normally mixtures offatty acids of varying chain length, this also applies to the fatty acidradicals in the sorbitol esters used according to the invention. Thesorbitol esters used according to the invention can also be alkoxylated,preferably ethoxylated.

[0027] In addition, it is possible to use anionic emulsifiers, such asethoxylated and nonethoxylated mono-, di- or triphosphoric esters, butalso cationic emulsifiers, such as mono-, di- and trialkyl quats andtheir polymeric derivatives.

[0028] Likewise suitable are mixtures of compounds of two or more ofthese classes of substance.

[0029] As well as comprising AMPS copolymer, the dispersions accordingto the invention can comprise one or more oils, preferably from thegroup of hydrocarbons, ester oils, vegetable oils and silicone oils.

[0030] The oils used according to the invention include hydrocarbon oilswith linear or branched, saturated or unsaturated C₇-C₄₀-carbon chains,for example Vaseline, dodecane, isododecane, cholesterol, lanolin,hydrogenated polyisobutylenes, docosanes, hexadecane, isohexadecane,paraffins and isoparaffins;

[0031] oils of vegetable origin, in particular liquid triglycerides,such as sunflower oil, corn oil, soybean oil, rice oil, jojoba oil,babusscu oil, pumpkin oil, grapeseed oil, sesame oil, walnut oil,apricot oil, macadamia oil, avocado oil, sweet almond oil, lady's smockoil, castor oil, olive oil, groundnut oil, rapeseed oil and coconut oil;

[0032] oils of animal origin, for example beef tallow, perhydrosqualene,lanolin;

[0033] synthetic oils, such as purcellin oil, linear and/or branchedfatty alcohols and fatty acid esters, preferably Guerbet alcohols having6 to 18, preferably 8 to 10, carbon atoms; esters of linear(C₆-C₁₃)-fatty acids with linear (C₆-C₂₀)-fatty alcohols; esters ofbranched (C₆-C₁₃)-carboxylic acids with linear (C₆-C₂₀)-fatty alcohols,esters of linear (C₆-C₁₈)-fatty acids with branched alcohols, inparticular 2-ethylhexanol; esters of linear and/or branched fatty acidswith polyhydric alcohols (such as, for example, dimerdiol or trimerdiol)and/or Guerbet alcohols; alcohol esters of C₁-C₁₀-carboxylic acids orC₂-C₃₀-dicarboxylic acids, C₁-C₃₀-carboxylic monoesters and polyestersof sugar, C₁-C₃₀-monoesters and polyesters of glycerol;

[0034] waxes, such as beeswax, paraffin wax or microcrystalline waxes,optionally in combination with hydrophilic waxes, such as, for example,cetylstearyl alcohol; fluorinated and perfluorinated oils;

[0035] Monoglycerides of C₁-C₃₀-carboxylic acids, diglycerides ofC₁-C₃₀-carboxylic acids, triglycerides of C₁-C₃₀-carboxylic acids, forexample triglycerides of caprylic/capric acids, ethylene glycolmonoesters of C₁-C₃₀-carboxylic acids, ethylene glycol diesters ofC₁-C₃₀-carboxylic acids, propylene glycol monoesters ofC₁-C₃₀-carboxylic acids, propylene glycol diesters of C₁-C₃₀-carboxylicacids, and propoxylated and ethoxylated derivatives of theabovementioned classes of compound.

[0036] Suitable silicone oils are dimethylpolysiloxanes,cyclomethicones, polydialkylsiloxanes R₃SiO(R₂SiO)xSiR₃, where R is amethyl and ethyl, particularly preferably methyl, and x is a number from2 to 500, for example dimethicones available under the tradenamesVICASIL (General Electric Company), DOW CORNING 200, DOW CORNING 225,DOW CORNING 200 (Dow Corning Corporation). Trimethylsiloxysilicates[(CH₂)₃SiO)_(1/2)]x[SiO₂]y, where x is a number from 1 to 500 and y is anumber from 1 to 500. Dimethiconoles R₃SiO[R₂SiO]xSiR₂OH andHOR₂SiO[R₂SiO]xSiR₂OH, where R is methyl or ethyl and x is a number upto 500, polyalkylarylsiloxanes, for example polymethylphenylsiloxanesobtainable under the tradenames SF 1075 METHYLPHENYL FLUID (GeneralElectric Company) and 556 COSMETIC GRADE PHENYL TRIMETHICONE FLUID (DowCorning Corporation), polydiarylsiloxanes, silicone resins, cyclicsilicones and amino-, fatty acid-, alcohol-, polyether-, epoxy-,fluorine- and/or alkyl-modified silicone compounds, and alsopolyethersiloxane copolymers, as described in U.S. Pat. No. 5,104,645and the specifications cited therein, which may either be in liquid formor in resin form at room temperature.

[0037] The dispersion concentrates according to the invention can beprepared in various ways, an inverse emulsion polymerization or aninverse mini-emulsion polymerization being as preferred as a physicalmixing of AMPS copolymer with oil/emulsifier phase and optionally waterphase. The physical mixing is preferably carried out by mixing oil phaseand emulsifier(s) at 10 to 60° C., preferably at room temperature, thenadding AMPS copolymer(s) to about 40% by weight of the oil/emulsifierphase over a period of from 10 to 60 min, preferably about 30 min, withvigorous stirring. During this, a homogeneous paste forms. If necessary,a small amount of water can be added to improve processing. Then, theremaining oil/emulsifier phase is added with stirring and the mixture isstirred to homogeneity for a number of hours. A liquid, pourabledispersion is formed.

[0038] The dispersion concentrates according to the invention aresuitable as thickener, bodying agent, emulsifier, solubilizer,dispersant, lubricant, adhesive, conditioner and/or stabilizer—in anexcellent manner for the formulation of cosmetic, pharmaceutical anddermatological compositions, in particular of oil-in-water emulsions inthe form of creams, lotions, cleansing milk, cream gels, sprayemulsions, e.g. body lotions, aftersun lotions, sunscreen compositionsand deodorant sprays.

[0039] The dispersion concentrates according to the invention are usedin the cosmetic and pharmaceutical preparations in amounts by weightsuch that polymer concentrations are from 0.01 to 10% by weight,preferably 0.1 to 5% by weight, particularly preferably 0.5 to 3% byweight, based on the finished compositions, result.

[0040] The compositions according to the invention can comprise anionic,cationic, nonionic, zwitterionic and/or amphoteric surfactants, and alsofurther auxiliaries and additives, cationic polymers, film formers,superfatting agents, stabilizers, biogenic active ingredients, glycerol,preservatives, pearlizing agents, dyes and fragrances, solvents,opacifiers, and also protein derivatives, such as gelatin, collagenhydrolysates, natural and synthetic-based polypeptides, egg yolk,lecithin, lanolin and lanolin derivatives, fatty alcohols, silicones,deodorizing agents, substances with keratolytic and keratoplasticaction, enzymes and carrier substances. Furthermore, antimicrobiallyeffective agents can be added to the compositions according to theinvention.

[0041] In addition, the compositions according to the invention cancomprise organic solvents. In principle, suitable organic solvents areall mono- or polyhydric alcohols. Preference is given to using alcoholshaving 1 to 4 carbon atoms, such as ethanol, propanol, isopropanol,n-butanol, isobutanol, t-butanol, glycerol and mixtures of saidalcohols. Further preferred alcohols are polyethylene glycols with arelative molecular mass below 2000. In particular, the use ofpolyethylene glycol with a relative molecular mass between 200 and 600and in amounts up to 45% by weight and of polyethylene glycol with arelative molecular mass between 400 and 600 in amounts of from 5 to 25%by weight is preferred. Further suitable solvents are, for example,triacetin (glycerol triacetate) and 1-methoxy-2-propanol. Short-chainanionic surfactants, in particular arylsulfonates, for example cumene-or toluenesulfonate, have a hydrotropic effect.

[0042] The following examples of dispersion concentrates with AMPSpolymers serve to illustrate the subject matter of the invention in moredetail without limiting it thereto (the percentages are percentages byweight).

[0043] Various base formulations with different emulsifier and oilconcentrations were prepared. The resulting polymer dispersions wereassessed according to appearance, viscosity and stability (sedimentationupon storage at 25° C. for 3 weeks). Table 1 shows examples ofdispersion concentrates which are flowable and storage-stable. TABLE 1Product name A B C D Hostacerin AMPS 32 36 40 30 Hostacerin DGI 30 3 51Hostaphat KL 340 D 18 18 2 13 Emulsogen SRO 30 Mineral oil,low-viscosity 10 27.5 6 Isopropyl palmitate 10 27.5 Myritol 318 16

[0044] The numbers are percentages by weight.

[0045] A. Mix oil and/or emulsifier component 3-8 and initiallyintroduce one third of the solution.

[0046] B. Over the course of half an hour, add polymer 1-2 with stirringat 400 rpm.

[0047] C. After-stir for half an hour then add the remaining solution ofA.

[0048] D. After-stir for a further 5 hours. TABLE 2 Hostacerin AMPSAmmonium polyacryloyldimethyltaurte Hostacerin DGI Polyglyceryl-2sesquiisostearate Hostaphat KL 340 D Trilaureth-4 phosphate EmulsogenSRO Rapeseed oil sorbitol esters Myritol 318 Caprylic/caprictriglyceride

[0049] Examples of cosmetic preparations based on the dispersionconcentrates according to the invention.

EXAMPLE 1 Moisturizing Lotion

[0050] A Almond oil 7.00% Cyclomethicones 5.00% B Dispersion concentrateA 4.00% C Glycerol 7.00% Water ad 100%  Preservative q.s. D Fragrance0.30%

[0051] Preparation

[0052] I Mix A and B.

[0053] II Stir solution C into 1.

[0054] III Add D to II.

[0055] IV Homogenize

[0056] V pH 5.5

EXAMPLE 2 Sunscreen Lotion

[0057] A Vaseline 5.00% Paraffin oil 10.00%  Dispersion concentrate B2.00% Tocopheryl acetate 1.00% Octyl methoxycinnamate 2.00% Parsol 17890.20% B Ethanol 10.00%  C Butylene glycol 5.00% Water ad 100% 

[0058] Preparation

[0059] I A and C are heated separately to 75° C., then combined andcooled to 65° C. with stirring, homogenized and further cooled to 35°C.,

[0060] II Stir B into I, homogenize and cool to room temperature

EXAMPLE 3 O/W Skin Milk

[0061] Composition A Isopropyl palmitate 4.00% Almond oil 5.00% 4.00%Wheatgerm oil 1.00% Cetearyl isononanoate 8.00% ® Cetiol SN (Henkel) BDispersion concentrate C 1.50% C Water ad 100%  D Fragrances 0.30%

[0062] Preparation

[0063] I Add B to A with stirring

[0064] II Stir C and D into I

[0065] III Homogenize emulsion

1. A stable dispersion concentrate comprising: I) 5 to 80% by weight ofa polymer which, in random distribution, consists of 90 to 99.99% byweight of monomers of the formula (1) H₂C=CHCONHC(CH₃)₂CH₂SO₃X  (1)  and0.01 to 10% by weight of crosslinking structures originating frommonomers with at least two olefinic double bonds, where X is a cation ora mixture of cations, and X must consist of not more than 10 mol % ofprotons, II) 20 to 95% by weight of one or more emulsifiers and/or anoil phase, and III) 0 to 30% by weight of water.
 2. The dispersionconcentrate as claimed in claim 1, wherein the polymer has crosslinkingstructures derived from acrylic or methacrylic allyl esters, dipropyleneglycol diallyl ether, polyglycol diallyl ether, triethylene glycoldivinyl ether, hydroquinone diallyl ether, tetraallyloxyethane or otherallyl or vinyl ethers of multifunctional alcohols, tetraethylene glycoldiacrylate, triallylamine, trimethylolpropane diallyl ether,methylenebisacrylamide, divinylbenzene or trimethylolpropanetri(meth)acrylate.
 3. The dispersion concentrate as claimed in claim 1,which comprises 10 to 80% by weight of the polymer.
 4. The dispersionconcentrate as claimed in claim 1, which comprises 20 to 60% by weightof the polymer.
 5. The dispersion concentrate as claimed in claim 1,which comprises 30 to 40% by weight of the polymer.
 6. The dispersionconcentrate as claimed in claim 1, which comprises 40 to 80% by weightof emulsifier and/or oil phase.
 7. The dispersion concentrate as claimedin claim 1, which comprises 60 to 70% by weight of emulsifier and/or oilphase.
 8. The dispersion concentrate as claimed in claim 1, whichcomprises 0 to 10% by weight of water.
 9. The dispersion concentrate asclaimed in claim 1, which comprises 0 to 5% by weight of water.
 10. Acosmetic, pharmaceutical or dermatological preparation comprising adispersion concentrate as claimed in claim
 1. 11. A cosmetic,pharmaceutical or dermatological preparation in the form of anoil-in-water emulsion comprising a dispersion concentrate as claimed inclaim 1.